Maxwell 3000F supercap


Official specifications: Maxwell%203000F%20supercap-info

Supercaps are a alternative to batteries at least in some cases, but their abilities are very different. I have performed the test as a battery test, making it easy to compare to batteries.
Something to note:
Supercaps has a fairly low voltage rating, for higher voltage they must be used in series and this will require a balancing circuit.
This type of supercap can handle extremely high current both charging and discharging.
The discharge and charge curve is linear and the capacitor can be discharge to zero without damage.
The capacitor has a fairly high self discharge.

DSC_4301 DSC_4302



A size comparison to AA and 18650 cells. The AA cell contains about the same energy as the capacitor, the 18650 contains nearly four times the energy.

Note: The 20A and 30A discharge are not 20/30A all the way down. I can only maintain 30A down to 1.9 volt and 20A down to 1.2 volt.


The discharge is very linear and can go all the way to zero volts.






The sag is not really due to current, but because the capacitor is discharged.


Charging is also linear.


This capacitor is fairly large and does not store more energy than a AA battery, it is not really a good replacement for most batteries.
This capacitor is designed to be used in cars or other transportation systems.

Notes and links

How is the test done and how to read the charts
Battery test main index